# US 11,305,381 B2 · Welding method

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- Number: US 11,305,381 B2
- Document ID: US11305381B2
- Status: Granted
- Kind: B2
- Application number: 16/601,000
- Filed: 2019-10-14
- Published: 2020-04-23
- Granted: 2022-04-19
- Earliest claimed: 2018-10-19
- Assignees: Futaba Industrial Co., Ltd.
- Applicants: Futaba Industrial Co., Ltd.
- Inventors: Toru Kobayashi
- Web page: https://patentgrep.com/patent/US11305381B2

## CPC

- B23K 26/0643: {comprising mirrors}
- B23K 26/244: Overlap seam welding
- B23K 26/02: Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K 26/082: Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
- B23K 26/22: Spot welding
- B23K 26/26: of rectilinear seams
- B23K 26/32: taking account of the properties of the material involved
- B23K 26/323: involving parts made of dissimilar metallic material
- B23K 37/0408: {for planar work}
- B23K 2101/18: Sheet panels
- B23K 2103/04: Steel {or steel} alloys
- B23K 2103/10: Aluminium or alloys thereof
- B23K 2103/20: Ferrous alloys and aluminium or alloys thereof
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

## Abstract

One aspect of the present disclosure is a welding method including welding an upper plate and a lower plate overlapped with the upper plate by irradiating a surface of the upper plate with a laser beam. The welding includes forming a main welding path that intersects a welding advancing direction and that includes turning points. The upper plate and the lower plate are arranged in an inclined manner with respect to a horizontal plane when viewed parallel to the welding advancing direction. In the forming the main welding path, an amount of energy applied by the laser beam in an area in a neighborhood of the turning point on a vertically upper side is designed to be larger than an amount of energy applied by the laser beam in an area in a neighborhood of the turning point on a vertically lower side.

## Claims

### Claim 1

A welding method comprising welding an upper plate and a lower plate overlapped with the upper plate by irradiating a surface of the upper plate with a laser beam,
the welding comprising:
forming a main welding path that intersects a welding advancing direction and that comprises turning points; and
forming an auxiliary welding path, which is continuous and comprises a reciprocating or circling path, prior to the forming the main welding path,
the upper plate and the lower plate being arranged in an inclined manner with respect to a horizontal plane when viewed parallel to the welding advancing direction, and
in the forming the main welding path, an amount of energy applied by the laser beam in an area in a neighborhood of at least one of the turning points on a vertically upper side being designed to be larger than an amount of energy applied by the laser beam in an area in a neighborhood of at least one of the turning points on a vertically lower side,
wherein the main welding path comprises:
an initial region continuous from the auxiliary welding path; and
a subsequent region that is provided on a more forward side of the welding advancing direction than the initial region and that has a larger turnaround pitch along the welding advancing direction than the initial region.

### Claim 2 (depends on 1)

The welding method according to claim 1,
wherein, in the forming the main welding path, a welding speed in the area in the neighborhood of at least one of the turning points on the vertically upper side is designed to be lower than a welding speed in the area in the neighborhood of at least one of the turning points on the vertically lower side.

### Claim 3 (depends on 2)

The welding method according to claim 2,
wherein, in the forming the main welding path, movement of the laser beam is stopped for a specified period of time in the area in the neighborhood of at least one of the turning points on the vertically upper side while irradiation with the laser beam is continued.

### Claim 4 (depends on 1)

The welding method according to claim 1,
wherein the welding further comprises stopping irradiation with the laser beam after formation of the main welding path and then performing re-irradiation.

### Claim 5 (depends on 5)

The welding method according to claim 5claim 1,
wherein the auxiliary welding path has a circular shapethe circling path.

### Claim 6 (depends on 4)

The welding method according to claim 4,
wherein output of the laser beam in the performing the re-irradiation is the same as an output of the laser beam in the forming the main welding path.

### Claim 7 (depends on 1)

The welding method according to claim 1,
wherein the welding advancing direction is linear.